This invention relates to a battery and a related method and, more particularly, a battery, which has a high energy density and is small in size and lightweight in structure to be available as an electric power source to supply large energy, and its related method.
In recent years, with an increasing concern for environmental consciousness, there have been significant movements in shift of power sources of automotive vehicles from engines utilizing fossil fuel to motors utilizing electric energy. For this reason, there have been rapid developments in technologies of batteries playing roles as the power sources of the motors.
The automotive vehicles are expected to be installed with the batteries, which are small in size, lightweight in structure with a capability of charging and discharging large electric power at frequent cycles, and excellent vibration-proof property and heat radiation characteristic.
Japanese Patent Application Laid-Open Publication No. 2000-195480 (see paragraph numbers 0014 to 0029 and FIGS. 1, 2 and 4) discloses a battery. In particular, the battery has a structure that includes a plurality of flat-shaped unit cells, electrically connected in series, parallel and series and parallel, which are disposed in a thickness direction of the unit cells at given intervals, and pressurizing members located between the unit cells of a stack to pressurize the unit cells on both sides of the stack whereupon the plurality of unit cells are fastened by an outer sheath member. With such a structure, attempts have been made to cause the unit cells to have favorable heat radiating characteristics to provide a battery with improved cyclic characteristic and rate characteristic.